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Chinese Alcohol Spirit Production Techniques

Fermentation techniques for distilled spirits originated from rice wine production. But the distillation technique made the fermentation processes of distilled spirits more diversified.Li Shizhen, a famous pharmacologist of Ming dynasty, recorded a production process of rice spirit in his book "Benchao Gangmu" (published in about 1578 A.D.). He wrote in his book: "The finished rice wine and rice wine mash could be used for production of spirit by distillation. At first, the rice wine or rice wine mash were placed in a pot, then heat the pot to let the hot vapour rise up, collect the condensate with a vessel". "The glutinous rice, long-grained nonglutinous rice, mazine, and barley are suitable for spirit production. The raw materials are steamed firstly, then, after being cooled, they are mixed with Qu (Qu). The mixture mash was placed into the fermentation vessels. After 7 day's fermentation, the fermented mash are taken out to be distilled; Collect the condensate which is like water and tastes strong." Obviously, at that time, the fermentation process for spirits was similar to that of rice- wine.People may be satisfied with the strong drinks simply made from the using of distillation technique.
The production of rice spirits in South China, such as the well-known Guiling Shanhua Spirit, kept using the same method described above until the first half of this century. The whole process is divided into two phasese. During the first phase when thefermenting grains are in solid state, the microorganisms from Qu are propagated on the steamed rice grains and the starch contained in the rice grains is partly hydrolyzed to dextrin. Then in the second phase, some water is added into the fermenting mash which turn to semi-solid state. The semi-solid state favours the fermentation of sugar by yeasts to produce ethanol. The fermentation time was about 7 days, and the flowchart of the production process is given below.

"Fen-flavour Spirit" has been a traditional process. As mentionedabove, The "FENJIU" produced in "Xinghua-cun Fenjiu Corporation", ShanxiProvince is accepted as the representative. The process of "FENJIU"is characterized by "pure" and "clean". For example, the husk which is used as fillings in distillation operation should be steamed to expel the unfavourable smell. the fermentation vessels should be ceramic vats.The fermented grains mixed with only small amount of steamed husk is distilled spearatly, without any fresh grains being added ( this isobviously different from Maotai-falvour Spirit or Luzhou-flavour Spirit).
The brewing technique of so-called 'QINGZHA" method'( a particular process for "Fen-flavour Spirit" production) may be derived from the the simple one developed in Ming Dynasty with the improvments which are characterized by twice fermentation and twice distillation of the fermented grains aimed at increasing the yield of ethanol.
The production porcess of "Fen-flavour Spirit" is summerized as follows:

Among most of high quality spirits produced by using DA- Qu as saccharifying and fermenting agent, The output of Luzhou- flavour Spirit is the biggest.
When the process of Luzhou flavour spirit was developed is still unclear. there are several evidences indicating that the process atleast existed in Ming Dynasy. In a secret recipe of producing the Luzhou flavour spirit discovered in Yibing District, Sichuan Province,the particular process was recorded. The secret recipe is identified to be handed down from Ming Dynasty. Another evidence is that an old fermenting pit in Wuliangye Distillery, Yibin District, Sichuan Province has been proved to be the oldest fermenting pit of about 500 years old.
The production method to produce Luzhou- flavour Spirit is a repeated-fed batch fermentation process (or recycling fermentation process) in which part of fresh grains is mixed with the fermented and distilled grains, then the mixture is refermented. A part of distilled grains was discharged. The technique was probably regarded as a economic one because of reuse some starch remaining in the spent grains.Actually, the quality of the spirits produced in this method was improved greatly. The flowdiagram of Luzhou flavour Spirit production is given in the Fig 4.4.3-1

The characteristic flavour of Luzhou flavour spirit is owingto the substance of hexanoate acetate in the spirit. There are two kinds of traditional fermentation vessels: ceramic vat and ferentation pit for the fermentation, and the latter is used in Luzhou-flavour spirit production, the former is used in Fen- flavour spirit production. The fermentation vessels are main factor affecting spirit's flavor types. Ceramic vessels have been widely used in rice wine breweries. Why did the brewmasters choose mud pit as the fermentation vessels for spirit production? Nobody could answerthis question before 1950's, except that the special flavour of the Luzhou-flavour spirit was regarded to be linked with the fermentation pits. Now, scientists have revealed a part of secrets of the fermentation pits: some microbes grown in the mud are resposible for the special Luzhou-flavour formation, especially the anearobic bacteriathat can produce hexanoic acid. Based on the discovery, a series of new techniques has developed, including "Man- made cellar" using the technique of cultivation of useful microorganisms in mud ; the fermentation pit with multi-layers of fermentation pit mud ,fermenting grains twice at the bottom of the fermentation pit.
The so called " five- batch steaming/distillation process " , Multiple feedings solid fermentation process) might have been developed before Qing Dynasty. This process is still a very popular one employed in most Luzhou-flavour spirit distilleries. We shall describe the traditional process in brief here. The fermentation substrates in the fermentation pit are divided into four parts :fermenting grains of high starch content ( two parts) in which relatively large amount of fresh grains is added, fermenting grains of low starch content (one part) in which small amount of fresh grains is added, and spent grains (one part) in which no fresh grain is added . The four parts of fermentation substrates are placed in the fermentation pit separately, all mixed with DA- Qu powders. After fermenting for a period of time (usually at least one month), the four parts of fermented grains are mixed with fresh grains and/or fillings in appropriate proportions to get five parts of mixed grains which are to be separately processed by distilled/steamed in a distiller ( at the same time of distillation, the fresh grains in the mixed grains is steamed). After distillation/steaming, a part of spent grains containing low content of starch is discarded, and four parts of mixed grains are cooled, mixed with Da Qu powders, then placed in fermentation pits again to start another cycle of the process. The arrangement of this process are given below:

Maotai Spirit, produced in Maotai, Renhuan County, Guizhou Province, is the most famous spirit in China. The spirit remaining in the winecup standing over a night has no significant change in flavour. After drinking the Maotai Spirit, the winecup still send forth a delicate fragrance overnight.
"A annual of Zhunyi Prefecture" edited in 1939 recorded the Maotai Spirit production techniques: "Maotai spirit, …, produced in Maotai Cun, Renhuan prefecture, ranked the first in Guizhou Province … …." The raw materials for Maotai Spirit production is sorghum. After being cooked, sorghum is mixed with Da Qu, and then is put into fermentation pits for about 1 month. Then the fermented grains are taken out to be distilled. The distilled grains still containing a lot of residual starch are returned back to the fermentation pits again after being mixed with Da Qu. Repeat this process for several times, then spirits collected in every batch is stored separately.
After the founding of the People's Republic of China, the Maotai Spirit production process had been summerized. The details are not exposed to the public. We describe in brief the basic process as follows.
The process is characterized by "high temperature". For example, the Da-Qu used for Maotai Spirit production is incubated in high temperature above 55 ℃, the raw materials are heaped up at high temperature before fermentation, The distillation process is operated at high temperature. A complete fermentation cycle lasts one year during which, the raw materials are added in two batches, fermentation of the grains are repeated eight times, distillation of the fermented grains is operated seven times. Some distilled spirits(usually with a light flavour ) are returned to the fermenting grains.
The principle raw material is Chinese Sorghum. The DA-Qu used is prepared from wheat naturally inoculated with various species of microorganisms and incubated at high temperature ( the temperature during incubation each may to 65 ℃). The ratio of Da- Qu to raw material, Chinese Sorghum, is almost 1: 1, the highest proportion compared with other types of spirits.
The fermentation vessels for Maotai Spirit are classified into tw o types: clay pit, stone pit the bottom of which is based on clay.
The production process may be simply summrized as follows: